Different pixel strips and strips use different control chips inside them. There are quite a few types and most of them are not directly compatible with each other.
So, you may see specs that say a controller suits 6803, 2801, 2811, etc. This means the controller outputs signals that those particular pixels can understand.
When you buy pixel strip, strings or modules, they will specify the type of control they use. If they don't, they may be "dumb" type that can't be controlled individually.